The study looked at how trace elements in municipal solid waste incineration fly ash can affect the environment. They tested different leaching methods to see how much arsenic and barium were released. They found that arsenic and barium levels exceeded safe drinking water standards in some tests. The amount of arsenic released decreased as the liquid-to-solid ratio increased. Barium leaching was affected by pH levels, with higher levels at pH 11.3. Boron and barium levels were not affected by pH until it reached 9. Copper levels decreased as pH increased.